A liquid crystal display (LCD) is used in various electric devices such as a computer monitor, a television, a mobile communication terminal, a navigation, etc.
Because the LCD does not emit light by itself, a backlight unit for providing light to the LCD is used at the rear of the LCD.
Although a cold cathode fluorescent lamp (CCFL) as a backlight unit has been used as a light source until now, a light emitting diode (LED) becomes widely used recently.
The LED is used as a backlight unit of the LCD and also as light source units of various electron devices requiring light and lightening devices.